A Mexican diva aglow with spirit

Mexican singer Lila Downs opened her concert at the Echo on Wednesday with a toast of mescal, the mystical firewater with ancient, indigenous roots in southern Mexico. A bottle of the powerful brew, along with plastic shot glasses, was passed around the packed crowd at the small Sunset Boulevard club, turned into a muggy hothouse by the current heat wave.

A resplendent Downs, her black hair in two long braids, raised her glass and thanked people for “coming and communing with us.” An unusual but appropriate way to open a hypnotic 90-minute concert that, more than a show, was a gathering of the faithful.

Downs’ cross-cultural appeal, evident from the multicultural makeup of Wednesday’s audience, arises in part from outsiders’ fascination with her native Oaxaca, a stronghold of Indian culture. Visitors still recall discovering her there, lighting up a small club called El Sol y la Luna (the Sun and the Moon) with that wondrous voice.

“The thing that grabbed me was the way she lives her songs,” recalled longtime admirer and promoter Betto Arcos, who emceed Wednesday’s show.

That authenticity still comes through in Downs’ performance, which is imbued at moments with a spiritual quality. Her exceptional voice, ranging from a hoarse whisper to a powerful, piercing wail, adds to the sense that one is witnessing a natural wonder.

Talent and conviction allow Downs to take on issues -- about women and workers, migrants and warmongers -- without sounding preachy or political. She convinces us she cares.

Wednesday’s show was essentially a showcase for her new album, “Una Sangre/One Blood,” which represents a maturation of her folk/jazz fusion and a high point of her career. She was accompanied by her husband and co-writer, Paul Cohen, on keyboards and saxophone, with the terrific musicians from the album -- notably Celso Duarte, contributing a thrilling, rhythmic solo on harp.

Downs’ gut-wrenching version of “Paloma Negra,” the ranchera classic of lost love and heartbreak, had her reverent crowd whooping and hollering like mariachis in a cantina. But the night’s most affecting moment came with a tune that’s not on the album, Michel Legrand’s “You Must Believe in Spring.” Introducing the song, Downs said she had been living in New York the last year, feeling “a division among people” and finding solace in songs that “give me some hope.” With her eyes closed and her heart wide open, she sang the Alan and Marilyn Bergman lyrics like a prayer:

So in a world of snow, of things that come and go / where what you think you know, you can’t be certain of / you must believe in spring -- and love.

For the many fans left standing in line for Wednesday’s sold-out show, Downs headlines a return concert Oct. 9 at UCLA’s Royce Hall, which has air-conditioning that works.